Collapsible arch form



Patented Aug. l, 1922.

2 SHEETSjSHEET I.

G. A. COMPTUN. COLLAPSIBLE ARCH FORM APPLICATION FILED AUG.28, 1920.

;;a;f: ef:=ff :;f,

G. A. COMPTON. COLLAPSIBLE ARCH FORM.

APPLICATIDN FILED AUG.28, |920 GLENN A. COIIETON, F MINNEAPOLIS, MNNESOTA, ASSIGNOR TO NORTHFIELD IRON COMPANY, OF NORTHFIELD, MINNESOTA, A CORPORATION OF MINNESOTA.

COLLAPSIBLE ARCH FOB/IVI.

Specification of Letters Patent.

Patented Aug. 1, 1922.

To all who/m, t may concern:

Be it known that l, GLnNN A. Codieren, a citizen ot thek United States, residing at Minneapolis, in the county or' l-lennepin and State off lilinnesota, have invented certain new and Vuseful Improvements in Collapsible VArch Forms; and l dol hereby declare the Vfollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention. relates to improvements in collapsible arch forms, and is especially adapted for use in the construction ot concrete bridges, culverts, conduits and the like.

To the above end, generally stated, the

` invention consists of the novel devices and combinations of devices hereinafter described and delined in the claims.

,ln the accomiianyingdrawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Dveiller-ring to the drawings:

uF ig. l. is a view intransverse section showing the improved collapsible arch. form assembled to 'torni a semi-cylindrical or Roman arch;

Fig. 2 is a vietv corresponding to Fig. 1, with the exception that the parts are assembled to 'forni a substantially rectangular arch or opening;

Fig. 3 is a fragmentary view in side elevation off the parts as assembled in F ig. 1;

Fig. lf a 'fragmentary detail view with some parts sectioned on the line Ll--ll of Fig. 2;

llig. 5 is a fragmentarydetail vienT with some parts sectioned on the line 5--5 of F l;

Fig. G is a :fragmentary detail view partly in plan and partly in horizontal section taken on the line 6-6 of Fig. 5; and

Fig. i" is a perspective view ot one oic the supporting brackets.

Referring first to the improved collapsible arch form assembled in Fig. 1, the numeral 8 indicates sills, as shown arranged in two laterally spaced aligned pairs, and to each of said sills is rigidly secured two longitudinally spaced bearing brackets 9. Each bearing bracket 9 includes an upwardly curved stop linger 10, a lug 11, having on its upper face a cam surface 12,-

which extends under said stop nger, and a pair or' laterally projecting stop shoulders 13 on said lug located at. the upper extremity off the cam surface 12 and below the tree end of the stop linger 10. The stop linger 1() is notched outward of its free end to afford a seat 141, the purpose of which will presently appear. lt is important to note that the bearing brackets 9, on each sill 8, are arranged with their stop fingers projecting in the saine direction and longitudinally in resp-ect to the sill, and that the aligned sills are arranged end to end so that the two pairs of stop fingers project in opposite directions and outward in respect to the collapsible arch form.

Loosely supported on each laterally spaced pair off bearing brackets 9 is a semicylindrical arch bar 15, the ends of which rest on the horizontal flange of an angle tiebar 16 and are riveted or otherwise rigidly secured to the vertical flange thereof. As best shown in liig. 1, it 'will be noted that the ends ot the tie-bar 1G are extended outward o1' the arch bar 15, and the upper edge of the vertical flange of said tie-bar is notched to afford seats 1T and bevel shoulders 18, the former oi which are located close to the arch bar 15, and the latter of which are located at the outer extremities of said tie-loar.4 The horizontal flange of the tie-har 16 is provided, just inward of the connected ends ol the arch bar 15, with notches 19 of sufficient width to clear the stop shoulders 13, and said horizontal flange is further provided, at the intermediate portion oi each notch 19, with a no-tch 2O of such depth as to expose the lower edge of the vertical flange of said tiebar and of sufficient Width to receive the pairs of stop shoulders 13.

To mount the archbars on the bearing brackets 9, the saine are held in outwardly inclined positions with the lnotches 19 aligned with the pairs o1' stop shoulders 13, and the notches 2O aligned with the lugs 11. Then,by a downward movement of the arch bars 15, and at the same time. moving the 'tops thereof inward to aright the same, the exposed lower edge of the vertical ilangey of the tie-bar 16 will be carried onto the cam Surfaces 12. This upright movement of the arch vbars 15 Will carry one tace of the vertical llange, of the tie-bar 16, against the stop fingersv 10 and the stop surfaces 2l against the under faces of the stop shoulders 13. It will thus be seen that the arch bars 15 are securely interlocked with the bearing brackets 9 against transverse movement and against inward tipping movement.

`Coupling rods 22, having T-heads 23 at theirl ends, releasably connect the arch bars l5 andare detachably secured thereto by bifurcated hook-like coupling brackets 24. rigidly securedto the intermediate portions of said. archv bars. It will bev noted that each end arch bar l5 has only one coupling bracket 24;, and that each intermediate arch bar l5 has two coupling brackets 24, which ext-end in opposite directions. By reference to Figs. l and 2, it will be noted that the coupling rods 22 extend between the prongs vof the brackets 245; to hold said rods against lateral movement, and that the T- heads 23 extend transversely through said brackets and lock said coupling rods thereto against endwise movement. lt `will be noted, byV reference to Fig. 8, that the inter-- mediate coupling rod 22 holds the two intermediate arch bars l5 against outward swinging movement away from each other against the action of the cam surfaces 12. 'To release the intermediate coupling rod 22 andtlierebyallow the connected arch bars l5 to'fall outward iny opposite directions., there is intermediately. fulcrumed to one of said intermediate arch bars a lever 25 having atits inner end a striking or lifting head 26 located directly under one end of the intermediate coupling rod 22.. The outer end of the lever 25 is curved downward and has attached thereto an operating cable 27, which, in actual usage, will be of suflicient length to extend considerably outward over one end of the arch forni. The striking head 26 is of such weight as to hold the lever 25 in a position with said head in its lowerinost position, so that a pull on the operating cable 2T will lift the head 2G and cause the same to engage the coupling rod 22 and-lift the same out cf the respective coupling bracket 24.

Removably supported en the arch bars l5 is a plurality of longitudinal.l5T extended slats 28,- on which the material X, from which the arch is formed, is placed or poured. Each slat 28`has, at one of its longitudinal edges, a channel 29, at its other longitudinal. edge an inwardly turned 'fiange '30, and at ils transverse center, it is bent outward to forni a longitudinally extended reinforcingl` rib l'l.

VlThe slats 28 are loosely held on the arch hars 15 by first hanging two of said slats on the shoulders 18 by means of their channels 29 and with their flanges 30 bearing against the outer longitudinal edges of the sills 8 to prevent inward swinging movement thereof. Two otherslats are then placed on the arch bars l5 with "their flanges() seated in the.

channels 29 of the first two slats 28. The remaining slats are then secured on the arch bars l5 in the same manner that the last two Vslats are secured thereto. i/Vhen all of the slats 28 have been placed on the arch bars l5, there is a relatively narrow opening left therebetween, at the top of said arch bars, and this opening is closed by a ridge plate 32 having at one of its longitudinal edges an inturned flange 33 adapted to be seated in the channel 29 ofvone of the upper most slats 28. This ridge plate 32 is identical with the slats 28, with the exception that it has no channel 29, andits longitudinal edge opposite from the fiange 33 loosely rests on the underlying slat 28.

lWhen the collapsible form is properly set up and the arch X built thereover, said form is left a sufcient length of time to permit the material, from which the arch is constructed, to set. The collapsible form is then removed from the arch by first'drawing on the cable 27 to cause the head 2G to engage the intermediate coupling rod 22 and lift the respective end thereof from the coupling bracket 24, with which it is interlocked, as previously described. When the coupling rod 22 is released, the intermediate arch bars l5 u away from the arch, due to the action of the cam surfaces l2 on their tie-bars 16, and, at

simultaneously move downward the same time, the stop fingers lO cause said arch bars to swing outward. The releasing of the intermediate coupling rods 22 also releases the outer coupling rods 22, as they are anchored to the intermediate arch bars l5, and thereby allows the outer arch bars l5 to move downward and swing` outward with said intermediate arch bars. In case any of the slats should adhere to the formed arch, they may be easily detached therefrom.

Referring now to the collapsible arch form as assembled in Figs. 2, 4.-, 5 and 6, there is added to each arch bar l5 an angle bracket 34, preferably having oblique corners, to form a substantially rectangular arch Y. Each angle bracket 34- is formed, as shown, from an angle bar, the flanges of which are indicated by the numerals 85 and 36. The Vflanges 35 extend outward ofthe arch bar l5, to which they are applied, and the flanges 3G extend substantially parallel thereto. The lower ends of the flanges 35 terminate short of the corresponding ends of the flanges 86 to afford supporting shoulders 37 adaptedto enter the seats` 17 and support the angle brackets 34 from the arch tie-bar 16. On `tlieinner edges of the flanges at the lower ends thereof. are extensions or lugs 38 arranged to enter the seats l-l for engagement with the tie-bar 1G and stop fingers lOto hold the angle brackets 34E in upright positions on the arch bars `l5.

The upper ends of the flanges 35 overlap one another at the crown of the arch bar l5, and the upper ends of the flanges 36 termi- 'nate short of the corresponding ends of the flanges 35 to clear the coupling brackets Q4 and also per'mit said flanges 35 to be aligned.

rlhe slats 28 and 32 are secured to the angle brackets 34 in the same manner that said slats are secured to the arch bars l5. ln collapsing the arch form just described, the downward and outward movements of the arch bars l5 will release the angle bracmetsl-l and allow the same tc 'lull inward toward each other and awa from the slats 28 and 32.

ln Figs. l and Q, wooden forms Z are provided and spaced outward of the collapsible arch forms to determine the thickness of the arches and hold the materials X and Y while setting. These wooden forms form no part of my present invention, and may be dispensed with. ln some instances, the concrete may be poured directly against cut banks between which the collapsible arch form is placed, or the concrete may be mixed dry and spread over the slats when forming an arch. of the type shown in Fig. l.

l/Vhat I claim is:

l. A collapsible form for use in the construction of arches including a pair of laterally spaced bearing brackets having stop surfaces and inclined cam surfaces. and an arch bar supported on the cani surfaces and held in an upright position at the upper extremities thereof by the said stop surfaces, said arch bar having interlocking engagement with the bearing brackets to hold the same against tipping movement toward the stop surfaces.

2. A collapsible form for use in the construction of arches including ay pair of laterally spaced bearing brackets having stop surfaces and inclined cam surfaces, .and an larch bar supported on the cam surfaces and held in an upright position at the upper tremities thereof by the said stoy surfaces, said arch bar having interlocking engage-- ment with the bearing brackets to hold the same against tipping movement toward the stop surfaces and against transverse movement in respect to the bearing brackets.

.A collapsible form for use in the ronstruction of arches including` longitudinally spaced bearing brackets arranged in laterally spaced pairs, each of said bearing brackets havinw` a stop surface and an inclined cam surface, an arch bar supported on the cam surfaces of each laterally spaced. pair of bearing brackets, said arch bars being held in upright positions ou the upper extremities of the cam surfaces by the stop shoulders and having interlockingl engagement with the bearing brackets to hold VIthe arch bars against tipping movement toward the stop surfaces, the. laterally spaced bearingl brackets being turned in opposite directions with their cam surfaces facing outward, and acoupling rod connecting the tit arch bars for holding the saine against tioping movement away from the stop sur, l. A collapsible form for use in the construction of arches including longitudinally spacedl bearing brackets arranged in laterally spaced pairs,each of said bearing brackets havingastop surface and an inclined earn surface, an arch bar supporrer'il on the c; .1i surfaces of each laterally spaced pair of bearing brackets, saidy arch bars being held in upright positions on the upper extremit' is of the cam surfaces by the stop should-eis and having interlocking engagement with the bearing brackets to hold the arch bars against tipping movement toward the cam surfaces, the laterally spaced bearing brackets being turned in opposite directions with. their cam surfaces facing outward, a coupling rod connecting the arch bars for holding the same against tipping movement away from the stop surfaces, and means operative from a distant point to release the coupling rod from one of thc arch bars.

5. A collapsible form for use in the construction of arches including longitudinally spaced bearing brackets arranged in laterally spaced pairs, each of said bearing` brackets having a stop surface and an inclined cani surface, an arch bar supported on the cam surfaces of each laterally spaced pair of bearing brackets, said arch bars be` ing held in upright positions on the upper extremities of the cam surfaces by the stop shoulders and having interlocking engagement with the bearing brackets to hold the arch bars against tipping movement toward the cam surfaces, the laterally spaced bearing brackets being turned in opposite directions with their cam surfaces facing outv ward, a coupling rod,` coupling b 'ackets on the arch bars with which the couplingrods interlock, and mea-ns operative from a distant point to release the coupling rod from one of the couplino' brackets.

6. A collapsible form for use in the construction of arches including longitudinally spaced bearing brackets arranged in lat rally spaced pairs, each of said bearing brackets having a stop surface and an inclined cam surface, an arch bar supported on the cam surfaces of each laterally spaced pair of bearing brackets, said arch `bars being held in upright positions on the upper extremities of the cam surfaces by the stop shoulders and having interlocking engagement with the bearing brackets to hold the arch bars against tipping movement toward the cam surfaces, the laterally spaced bearing brackets being turned in opposite directions with their cam surfaces facing outward, a coupling rot., coupling brackets on the arch bars with which the coupling' rods interlock, a lever intermediately pivoted to one of the arch bars and having on one of its ends a lifting head arranged to engage trie coupling rod and litt one end `thereof trom the respective coupling; bracket, and

..n opeiatinrg cablelattached to thelever.

7. A collapsible term tor use in the construction ot arches includinga pair olf laterally spaced bearing brackets hai/*ing1 stop surfaces and inclined cam surfaces, an arch bar supported on the cam surfaces and held in an upright position at the upper `extremities thereof by the saidstop` surtaces, said arch bar having interlocking engagementwith thebearing brackets to hold the same against tipping movement 'toward the stop surfaces, and corner brackets loosely applied tothe arch bar and held in position thereon between said arch bars and the bearing` brackets.` v

8. A. collapsible form ilor use in the conf struction of arches ,including a pair ot' laterally spaced bearing lnacketshaving` stop surfaces and inclined cam surfaces, an arch bar supported onthe cam surfaces and held in an upright position atthe upper extremities thereof by the said stop surfaces7 said arch bar having interlockingV engagement with the bearing brackets to hold theA same against tipping` movement toward the stopA surfaces, and corner brackets having their lower ends loosely supported on seatson the arch bar with their upper ends in over-lap pingarrangement on the arch bar and held in position on the arch bar between said arch bars and the bearing brackets.

9. A collapsible form `tor use in the construction of arches including longitudinally spaced outer and intern'iediate bearing ets arranged in laterally spaced pairs, arch bar supported on each laterally spaced pair of bearing brackets for compound downvward and outward swinging` movements, an

intermediate coupling rod connecting the two intermediate arch bars, and end coupling rods connecting)r the end arch bars with the intermediate `arch baiis.

l0. A collapsible form tor use in the con struction of arches including` longitudinally spaced outer and intermediate bearing brackets arranged in laterally` spaced pairs, an arch bar supported lon each laterally spaced pair otbearing brackets for compound downward and outward swinging move-fric-ntsy an intermerliate=-couplingl rod connecting the two intermediate arch bars end coupling rods connecting` the end arch bars with the intermediate arch bars and means `tor releasing the intermediate couplingl rod trom `one ol.i the intermediate arch bars :from a distai'it point.

'struction of arches having in combination7 an arch bar having` an anc'le with horizontal and vertical flanges secured to its enda spaced bearingl brackets supportingthe ends or' said angles, each comprisinga cam suriiace on which the vertical tlange oli said angle is normally supported land said brackets having opposite portions engaging the sides ot said vertical liange, and the top o1 said horizontal flange to prevent tipping` ot said arch bar on said brackets.

13. A collapsible traniefor usein the construction o'f arches having; in combination`q an arch bar h aving an angle with horizontal and vertical lianges secured to its ends.

spaced bearing` brackets supporting said angles, each comprising cam surfaces on which the vertical flange ot said angle is normallyv supported, said brackets haring a portion engaging theouter side olI said vertical liange and an opposed `l`headed portion engaging thetop ol said horizontal flange and the inner side oll said vertical flange.

14. rlhe strnctureset iiortlir in claim lf3, said horizontal 'flange having notches in its edge of sutlicient width to pass over the cross member' oi? said 'lheach and a notch extendin@l trom said notch centrally 'thereof oil suilicient width to pass over the vertical portion olf said T-head.

ln testimony whereof l aliix my signature.

GLENN A. COMPTON.

il. A .collapsible 'form tor usein the con-` 

